Battery mounting structure for vehicle

ABSTRACT

A battery mounting structure is provided to prevent water intrusion into a clearance between a battery pack and a floor panel of a vehicle. The battery mounting structure comprises: frame members extending longitudinally on both sides of the vehicle; a floor panel disposed between the frame members; and a battery pack situated underneath the floor panel. A sealing member is interposed between a periphery of the battery pack and a portion extending from a member opposed to the battery pack, and a drain hole is formed in the sealing member to connect an inner side and an outer side of the sealing member.

CROSS REFERENCE TO RELATED APPLICATIONS

The present application is a division of U.S. application Ser. No.15/488,086, which claims the benefit of priority to Japanese PatentApplication No. 2016-085567 filed on Apr. 21, 2016 with the JapanesePatent Office, the entire contents of which are incorporated herein byreference in its entirety.

BACKGROUND

Field of the Disclosure

Embodiments of the present application relate to the art of a structurefor mounting a battery for storing electrical energy in a vehicle

Discussion of the Related Art

PCT international publication No. 2014/069270 describes one example of abattery mounting structure in vehicles. According to the teachings ofPCT international publication No. 2014/069270, a battery pack isdisposed on a vehicle-body strengthening member below a floor panel.Specifically, the strength member includes a pair of side membersextending in the longitudinal direction of the vehicle, and a pluralityof cross members for connecting the pair of side members in the widthdirection. The battery pack is disposed on those members, and thebattery pack includes a battery case formed of a battery pack lowerframe and a battery pack upper cover. In order to prevent intrusion ofwater and dust into the battery pack, a clearance between the batterypack lower frame and the battery pack upper cover is sealed by anannular seal member.

Since the battery case taught by PCT international publication No.2014/069270 is maintained in a liquid-tight condition, not only ashort-circuit of the battery but also rust formation of the battery casemay be prevented. However, water may intrude into a clearance betweenthe battery pack and the floor panel, and the intruding water mayaccumulate on the battery pack. Consequently, the intruding water maygive out unusual odor and the battery pack may be rusted the by theintruding water.

SUMMARY

Aspects of the present application have been conceived noting theforegoing technical problems, and it is therefore an object of thepresent application is to provide a battery mounting structure that canprevent water intrusion into a clearance between a battery pack and afloor panel of a vehicle.

Embodiments of the present disclosure relate to a battery mountingstructure for a vehicle, comprising: a pair of frame members extendingon both sides of the vehicle in a longitudinal direction; a floor paneldisposed between the frame members; and a battery pack having a cellstack formed of a plurality of single cells juxtaposed in apredetermined direction, that is situated underneath the floor panel. Inorder to achieve the above-explained objective, the battery mountingstructure is provided with: a sealing member that is interposed betweena periphery of the battery pack and a portion extending from a member ofthe vehicle including the frame member opposed to the battery pack; anda drain hole formed in the sealing member that provides a connectionbetween an inner side and an outer side of the sealing member in a widthdirection of the vehicle.

In a non-limiting embodiment, the portion extending from the memberincluding the frame member may be overlapped entirely on the peripheryof the battery pack, and the sealing member may be arranged entirely onthe periphery of the battery pack.

In a non-limiting embodiment, the battery mounting structure may befurther provided with a floor cross member extending in the widthdirection of the vehicle to connect the frame members, and a depressionthat is formed on a top face of the battery pack in the width directionof the vehicle along a contour of the floor cross member.

In a non-limiting embodiment, the drain hole may be formed in thesealing member at a portion between the depression and the floor crossmember.

In a non-limiting embodiment, the portion extending from the memberincluding the frame member includes an inner flange protruding inwardlyfrom at least the frame member.

In a non-limiting embodiment, the drain hole of the sealing member mayinclude end portions isolated away from each other. In addition, the endportions may be overlapped with each other within a predetermined regionwhile keeping a predetermined clearance therebetween in a directionalong the top face of the battery pack.

In a non-limiting embodiment, the battery pack may be disposed betweenthe frame members in such a manner that the single cells are juxtaposedin the width direction of the vehicle.

Thus, according to the embodiment of the present application, thesealing member is interposed between the periphery of the battery packand the portion extending from the member including the frame memberopposed to the battery pack. According to the embodiment of the presentapplication, therefore, water intrusion into a clearance between a floorpanel and the battery pack may be prevented. In addition, the drain holeis formed in the sealing member to provide a connection between an innerside and an outer side of the sealing member in a width direction of thevehicle. According to the first example, therefore, water condensed on asurface of the battery pack may be drained toward the frame member. Forthis reason, water accumulation on the top face of the battery pack maybe prevented.

BRIEF DESCRIPTION OF THE DRAWINGS

Features, aspects, and advantages of exemplary embodiments of thepresent invention will become better understood with reference to thefollowing description and accompanying drawings, which should not limitthe invention in any way.

FIG. 1 is a schematic illustration showing one example of a structure ofthe vehicle to which the battery mounting structure according to thepresent disclosure is applied;

FIG. 2 is a partial cross-sectional view showing a first example of thebattery mounting structure along the II-II line in FIG. 1;

FIG. 3 is a cross-sectional view along the III-III line in FIG. 1;

FIG. 4 is a schematic illustration showing one example of a drainstructure;

FIG. 5 is a schematic illustration showing another example of the drainstructure;

FIG. 6 is a perspective view showing one example of battery module;

FIG. 7 is a partial cross-sectional view showing a second example of thebattery mounting structure;

FIG. 8 is a partial cross-sectional view showing a third example of thebattery mounting structure; and

FIG. 9 is a partial cross-sectional view showing a fourth example of thebattery mounting structure.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT(S)

Hereinafter, embodiments of the present disclosure will be explainedwith reference to the accompanying drawings. Turning now to FIG. 1,there is shown one example of a bottom structure of a vehicle to whichthe battery mounting structure according to the present disclosure isapplied. In the vehicle 1 shown in FIG. 1, a converter 3, an inverter 4,a motor 5 as an induction motor, and a power transmission unit 6 arearranged in a front compartment 2, and a battery pack 7 as a secondarybattery is arranged under a floor panel. The converter 3 is adapted toincrease a voltage from the battery pack 7, and to apply the voltage tothe inverter 4 while stabilizing. The direct current power supplied fromthe battery pack 7 is converted into the alternate current power by theinverter 4, and further supplied to the motor 5 while controllingfrequency. An output torque of the motor 5 is transmitted to drivewheels 8 through the power transmission unit 6 while being increased ordecreased. Here, the inverter 4 may also be connected directly to thebattery pack 7 while omitting the converter 3.

In the vehicle 1, a right side sill 9 and a left side sill 10 serving asframe members extend longitudinally parallel to each other on both sidesof the vehicle 1 at the same level. Front ends of the right side sill 9and the left side sill 10 are connected through a front cross member 13as a lateral reinforcement member, and rear ends of the right side sill9 and the left side sill 10 are connected through a rear cross member 14as a lateral reinforcement member. In order to further reinforce theright side sill 9 and the left side sill 10, a first floor cross member11 and a second floor cross member 12 are disposed laterally underneatha floor panel between the right side sill 9 and the left side sill 10while keeping a predetermined clearance therebetween in the longitudinaldirection. Right ends of the first floor cross member 11 and the secondfloor cross member 12 are attached to the right side sill 9, and leftends of the first floor cross member 11 and the second floor crossmember 12 are attached to the left side sill 10. Each of the first floorcross member 11 and the second floor cross member 12 is a depressed beammember, and the first floor cross member 11 and the second floor crossmember 12 are connected to the right side sill 9 and the left side sill10 in such a manner that the depressions thereof are opened toward thefloor panel.

FIG. 2 shows a cross-section of the battery mounting structure accordingto the first example along II-II line in FIG. 1. As depicted in FIG. 2,a floor panel 15 is deposed above the battery pack 7. An inner flange 16protrudes from an inner side face of the right side sill 9 toward avehicle component, and a right side of the floor panel 15 is supportedby the inner flange 16 of the right side sill 9. Likewise, although notespecially shown in FIG. 2, the remaining sides of the floor panel 15are also supported by the inner flanges 16 of the left side sill 10, thefront cross member 13, and the rear cross member 14.

The battery pack 7 is disposed underneath the floor panel 15 between theright side sill 9 and the left side sill 10. The battery pack 7 includesa battery frame 17 as a hollow peripheral reinforcement member, and abox-shaped casing 18 for holding fuel cell stacks 28 therein. A heightof the battery frame 17 is shorter than that of the casing 18, and thebattery frame 17 is attached around a lower part of sidewalls 18 a ofthe casing 18 in such a manner as to align bottoms of the battery frame17 and the casing 18. That is, the battery frame 17 is expanded from thesidewalls 18 a of the casing 18. A lower inner corner of the right sidesill 9 is depressed to form a depression 19 to be engaged with thebattery frame 17, and at least an upper face 17 a of the battery frame17 is fixed to a lower face of the depression 19 by bolts or the like.In other words, the battery frame 17 is partially overlapped with theright side sill 9 in the width direction of the vehicle 1. Likewise,although not especially shown in FIG. 2, the depressions 19 are alsoformed on the lower inner corners of the left side sill 10, the frontcross member 13, and the rear cross member 14, and the depressions 19 ofthose members are also engaged with the battery frame 17 in a similarfashion.

The casing 18 is closed by a lid 18 b, and a periphery 20 of the lid 18b is entirely overlapped with the inner flanges 16 of the right sidesill 9, the left side sill 10, the front cross member 13, and the rearcross member 14. An annular sealing member 21 is interposed between anupper face of the periphery 20 of the lid 18 b and the inner flanges 16of the right side sill 9, the left side sill 10, the front cross member13, and the rear cross member 14.

FIG. 3 shows a cross-section of the battery mounting structure accordingto the first example along III-III line in FIG. 1. As illustrated inFIG. 3, the first floor cross member 11 and the second floor crossmember 12 are situated underneath the floor panel 15. In the lid 18 b ofthe casing 18, a first lateral depression 22 is formed in the widthdirection to hold the first floor cross member 11 therein, and a secondlateral depression 23 is formed in the width direction to hold thesecond floor cross member 12 therein. A lower face of the bottom of thecasing 18 is substantially flat and exposed to outside. Here, the boltsfixing the side sills 9 and 10 the battery pack 7 are omitted in FIG. 3for the sake of illustration.

In order to enhance rigidity of the casing 18, a first lateral reinforcemember 24 extends laterally between the right side sill 9 and the leftside sill 10 underneath the first floor cross member 11, and a secondlateral reinforce member 25 extends laterally between the right sidesill 9 and the left side sill 10 underneath the second floor crossmember 12. As illustrated in FIG. 3, the first lateral reinforce member24 and the second lateral reinforce member 25 are individually depressedupwardly.

For example, the sealing member 21 may be made of rubber material, andthe sealing member 21 is disposed entirely on the periphery 20 of thelid 18 b. As illustrated in FIG. 3, in the first lateral depression 22,the sealing member 21 is interposed between the lid 18 b of the casing18 and the first floor cross member 11. Likewise, in the second lateraldepression 23, the sealing member 21 is interposed between the lid 18 bof the casing 18 and the second floor cross member 12. In addition, adrain hole 26 is formed in each of the first lateral depression 22 andthe second lateral depression 23.

For example, as shown in FIG. 4, the drain hole 26 may be formed bypartially cutting the sealing member 21 in such a manner as to maintaina clearance between end portions 21 a. Instead, as shown in FIG. 5, theend portions 21 a may also be overlapped with each other within apredetermined region so as to form a crank-shaped drain hole 26.Optionally, a labyrinth structure may be employed to form the drain hole26. Alternatively, a plurality of the sealing member 21 may be arrangedin a circular manner on the lid 18 b of the casing 18 while keeping aclearance between end portions 21 a to form the drain hole 26 shown inFIG. 4 or 5 in the first lateral depression 22 and the second lateraldepression 23. In addition, the sealing member 21 may also be made ofresin or adhesive agent instead of rubber.

Turning back to FIG. 1, in the casing 18, five sets of battery modules27 are juxtaposed in the longitudinal direction at substantially regularintervals. The first lateral reinforce member 24 is disposed between thesecond and the third battery modules 27 from the front, and the secondlateral reinforce member 25 is disposed between the third and the fourthbattery modules 27 from the front. Each of the battery modules 27includes a cell stack in which a plurality of single cells arejuxtaposed in the width direction, and both ends of each of the batterymodule 27 is individually fixed to the casing 18. Optionally, a bottomof the battery module 27 may be fixed to side ends of the first lateralreinforce member 24 and the second lateral reinforce member 25.

Components of the battery module 27 as an all-solid battery are shown inFIG. 6 in more detail. As illustrated in FIG. 6, the battery module 27comprises a first end plate 29, a second end plate 30, a first tensionplate 31, a second tension plate 32, and a cell stack 28. Specifically,the fuel cell stack 28 is formed of a plurality of flat rectangularsingle cells 33 juxtaposed in the width direction of the vehicle 1. Eachof the single cells 33 includes a positive electrode, a negativeelectrode, a solid electrolyte interposed between the electrodes, apositive terminal connected to the positive electrode, and a negativeterminal connected to the negative electrode (neither of which areshown). The single cells 33 are connected in series, and the batterymodule 27 are connected to the motor 5 and a battery ECU through aharness (not shown).

The first end plate 29 and the second end plate 30 are situated on bothwidth ends of the cell stack 28. The first end plate 29 is provided witha pair of fixing plates 34 and 35 at both ends and the second end plate30 is provided with a pair of fixing plates 36 and 37 at both ends sothat the battery module 27 is fixed to the casing 18 by screwing bolts(not shown) into bolt-holes of the fixing plates 34, 35, 36 and 37.

The first tension plate 31 is attached to the first end plate 29 and thesecond end plate 30 above the cell stack 28 by bolts 38 and 39, and thesecond tension plate 32 is attached to the first end plate 29 and thesecond end plate 30 below the cell stack 28 by the bolts 38 and 39. Inorder to adjust a clamping force for bundling the cell stack 28 by thefirst end plate 29 and the second end plate 30, a shim 40 isindividually interposed between the first end plate 29 and the firsttension plate 31, and between the first end plate 29 and the secondtension plate 32. To this end, a thickness of the shim 40 may beadjusted in such a manner as to achieve a desired clamping force. Forexample, the clamping force for clamping the cell stack 28 by the firstend plate 29 and the second end plate 30 may be increased by increasingthickness of the shim 40.

Each of the battery modules 27 is individually connected with a batteryECU (not shown) through a wire harness, and the battery ECU isconfigured to stabilize the power output of the single cell 33 whileobserving voltage. Specifically, the battery ECU is attached to a frontface or a rear face of each of the battery modules 27 in thelongitudinal direction of the vehicle 1, and the battery modules 27 areconnected in parallel with one another to achieve a required capacity ofthe battery pack 7 to operate the motor 5.

Thus, in the battery mounting structure according to the first example,the sealing member 21 is disposed entirely on the periphery 20 of thelid 18 b of the casing 18 to fill the clearance between the lid 18 b andthe inner flanges 16 of the right side sill 9, the left side sill 10,the front cross member 13, and the rear cross member 14. According tothe first example, therefore, water intrusion into the clearance betweenthe floor panel 15 and the battery pack 7 may be prevented. In addition,the drain hole 26 is formed in the sealing member 21 in each of thefirst lateral depression 22 and the second lateral depression 23.According to the first example, therefore, water condensed in thebattery pack 7 flows into the first lateral depression 22 and the secondlateral depression 23, and drained to outside of the vehicle 1 throughthe drain holes 26. That is, water accumulation on the lid 18 b of thecasing 18 can be prevented. Further, since the first floor cross member11 and the second floor cross member 12 are disposed above the firstlateral reinforce member 24 and the second lateral reinforce member 25,the first lateral depression 22 and the second lateral depression 23 maybe formed without restricting an internal space of the casing 18 forarranging the battery modules 27.

Turning to FIG. 7, there is shown a cross-section of the batterymounting structure according to the second example in which the sealingmember 21 is interposed between the side right sill 9 and the batteryframe 17 and between the left side sill 10 and the battery frame 17.According to the second example, the sealing member 21 is arranged on anupper face 17 a of the battery frame 17 entirely around the casing 18.In the right side sill 9, the lower face of the depression 19 isdepressed in the longitudinal direction of the vehicle 1 to form asecond depression 41, and the sealing member 21 is interposed betweenthe upper face 17 a of the battery frame 17 and the lower face of thedepression 19 in the second depression 41. Likewise, although notespecially shown in FIG. 7, the second depression 41 is also formedindividually in the depressions 19 of the left side sill 10, the frontcross member 13, and the rear cross member 14, and the sealing member 21is interposed between the upper face 17 a of the battery frame 17 andthe lower face of the depression 19 in the second depression 41. In thesecond example, the floor panel 15 is attached only to the right sidesill 9 and the left side sill 10. The remaining structures are similarto those of the first example, and detailed explanations for the commonelements will be omitted by allotting common reference numerals thereto.In the second example, accordingly, the upper face 17 a of the batteryframe 17 corresponds to the “periphery” of the battery pack.

Thus, according to the second example, the sealing member 21 is situatedbelow the lid 18 b of the casing 18 so that water intrusion into thecasing 18 can be prevented more certainly. In addition, water condensedin the battery pack 7 also flows into the first lateral depression 22and the second lateral depression 23, and drained to outside of thevehicle 1 through the drain holes 26.

Turning to FIG. 8, there is shown a cross-section of the batterymounting structure according to the third example in which an interiormaterial 42 such as a noise absorbing material, a carpet and so on isarranged on the lid 18 b of the casing 18. In this case, the lid 18 b ofthe casing 18 also serves as the floor panel 15. The remainingstructures are similar to those of the first example shown in FIG. 2.According to the third example, therefore, a vehicle weight may belightened and number of parts may be reduced by thus omitting the floorpanel 15.

Turning to FIG. 9, there is shown the fourth example of the batterymounting structure in which the first floor cross member 11 and thesecond floor cross member 12 are disposed on the upper face of the floorpanel 15. As depicted in FIG. 9, according to the fourth example, bothof the first floor cross member 11 and the second floor cross member 12are depressed upwardly. The remaining structures are similar to those ofthe first example shown in FIG. 3. According to the fourth example,water condensed in the battery pack 7 also drained to outside of thevehicle 1 through the drain holes 26.

Although the above exemplary embodiment of the present application havebeen described, it will be understood by those skilled in the art thatthe present application should not be limited to the described exemplaryembodiment, and various changes and modifications can be made within thespirit and scope of the present application. For example, the batterymounting structures according to the foregoing examples may also beapplied to hybrid vehicles and plug-in hybrid vehicles in which a primemover includes an engine and at least one motor. In addition, thebattery mounting structures according to the foregoing examples may alsobe applied to electric vehicles in which each wheel is individuallydriven by own motor.

What is claimed is:
 1. A battery mounting structure, comprising: a pairof frame members extending in a vehicle longitudinal direction; a floorpanel between the pair of frame members and connected with the framemembers; a battery pack situated underneath the floor panel and disposedbetween the frame members, wherein the battery pack includes a batteryframe and a cell stack, the battery frame being disposed underneath theframe members and being connected with the frame members at a firstlocation; and a sealing member disposed at a second location, the secondlocation being disposed between the frame members and the battery framein a vehicle height direction and being located on a battery pack sideof the first location, wherein the sealing member has a drain hole inthe sealing member that connects an inner side of the sealing memberwith an outer side of the sealing member in a vehicle width direction.2. The battery mounting structure as claimed in claim 1, wherein adepression is in the frame members and the sealing member is provided onthe depression.
 3. The battery mounting structure as claimed in claim 1,wherein the drain hole of the sealing member includes end portionsisolated away from each other, and wherein the end portions areoverlapped with each other within a predetermined region while keeping apredetermined clearance therebetween in a direction parallel to the topface of the battery pack.
 4. The battery mounting structure as claimedin claim 1, wherein the cell stack comprises a plurality of singlecells, and the battery pack is between the frame members in such amanner that the single cells are juxtaposed in the vehicle widthdirection.
 5. The battery mounting structure as claimed in claim 1,wherein the battery pack includes a casing for holding the cell stacktherein that is integrally formed with the battery frame, and thebattery frame is attached around a lower part of sidewalls of the casingin such a manner as to align bottoms of the battery frame and thecasing.
 6. The battery mounting structure as claimed in claim 1, whereina lower inner corner of the frame member comprises a depression engagedwith the battery frame.
 7. The battery mounting structure as claimed inclaim 1, further comprising: a floor cross member extending in thevehicle width direction to connect the frame members; and a top face ofthe battery pack comprises a depression in the vehicle width directionalong a contour of the floor cross member.
 8. The battery mountingstructure as claimed in claim 7, further comprising a drain hole in thesealing member at a portion between the depression and the floor crossmember.
 9. A battery mounting structure, comprising: a pair of framemembers extending in a longitudinal direction; a battery pack betweenthe frame members, wherein the battery pack includes a battery frame anda cell stack, the battery frame being connected with the pair of framemembers at a first location such that at least one of the frame membersis over the battery frame; a sealing member between the frame membersand the battery frame such that the sealing member is between at leastone of the frame members and the battery frame at a second location on abattery pack side of the first location; and a drain hole in the sealingmember between the battery pack and the cross member.
 10. The batterymounting structure of claim 9, wherein the at least one frame member hasa recessed region with respect to the battery frame, and the sealingmember is in the recessed region.
 11. The battery mounting structure ofclaim 9, wherein the sealing member has a passage extending through thesealing member from a first side of the sealing member opposite to theat least one frame member to a second side of the sealing member facingthe at least one frame member.
 12. The battery mounting structure ofclaim 11, wherein the passage of the sealing member includes endportions of a material of the sealing member that are overlapped withone another.
 13. The battery mounting structure of claim 9, wherein thecell stack comprises a plurality of single cells, and the single cellsare juxtaposed in a direction extending from a first frame member of thepair of frame members to a second frame member of the pair of framemembers.
 14. The battery mounting structure of claim 9, wherein thebattery pack includes a casing, the cell stack is inside the casing, andthe battery frame extends away from the casing.
 15. The battery mountingstructure of claim 9, further comprising: a cross member connecting theframe members.
 16. A vehicle, comprising: a pair of frame membersextending in a length direction of the vehicle; at least two crossmembers connecting the frame members, the at least two cross membersextending in a width direction of the vehicle; a battery pack betweenthe frame members, wherein the battery pack includes a battery frame anda cell stack, the battery frame being connected with the pair of framemembers at a first location such that at least one of the frame membersis over the battery frame; and a sealing member between the framemembers and the battery frame, wherein the sealing member is between atleast one of the frame members and the battery frame at a secondlocation on a battery pack side of the first location, and the sealingmember has a drain hole extending from a battery pack side of thesealing member toward a frame member side of the sealing member.
 17. Thevehicle of claim 16, further comprising: a floor panel, wherein thebattery pack is beneath the floor panel in a height direction of thevehicle.